Comparative study of the high-pressure behavior of As, Sb, and Bi
Comparative study of the high-pressure behavior of As, Sb, and Bi
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DOI：
10.1021/ja020832s
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发表时间：
2002-12-25
影响因子：
15
通讯作者：
Norrestarrit, R
中科院分区：
文献类型：
--
作者：
Häussermann, U;Söderberg, K;Norrestarrit, R
用赝势和平面波基组从头算密度泛函方法研究了重15族元素As、Sb和Bi3种元素的高压行为。这些元素的高压构造序列以BiIII构造的产出为特征，BiIII构造是一种复杂的、无公度调制的主客体结构。我们用一个超晶胞来近似这个结构，它非常好地再现了实验上为不同元素建立的主客体结构的压力稳定范围。随着压力的增加，我们发现As、Sb和Bi的电子结构的占据能级中的d态混合(S-d杂化)越来越多。然而，S-d的混合仍处于较低水平。因此，复杂的中压结构的出现不能用压力引起的这些元素的价态变化来解释。相反，有人认为，BiIII结构是静电和能带能量对总能量贡献之间微妙相互作用的结果。在较重的15族元素的中压范围内，总能量的两个重要部分对结构稳定性的影响是相同的。
The high-pressure behavior of the heavier group 15 elements As, Sb, and Bi was investigated by means of ab initio density functional calculations employing pseudopotentials and a plane wave basis set. The high-pressure structural sequence of these elements is distinguished by the occurrence of the Bi-III structure, which is a complex, incommensurately modulated, host-guest structure. We approximated this structure by a supercell which reproduced the experimentally established pressure stability ranges of the host-guest structure for the different elements extremely well. With pressure we find an increasing admixture of d states (s-d hybridization) in the occupied levels of the electronic structure of As, Sb, and Bi. However, the s-d mixing remains at a low level. Thus, the emergence of a complex intermediate pressure structure cannot be explained by a pressure-induced altered valence state for these elements. Instead, it is argued that the Bi-III structure is a consequence of a delicate interplay between the electrostatic and the band energy contribution to the total energy. In the intermediate pressure range of heavier group 15 elements, both important parts of the total energy account equally for structural stability.